TW201510232A - Sintered body, and sputtering target for magnetic recording film formation use which comprises said sintered body - Google Patents

Abstract

A sintered body which contains at least cobalt as a metal and is composed of boron and/or at least one metal selected from platinum group elements or an alloy of the metal and an oxide, said sintered body being characterized in that at least one compound selected from Cr(BO3), Co2B2O5 and Co3B2O6 is contained in a phase composed of the oxide. A sintered body in which a compound selected from Cr(BO3), Co2B2O5 and Co3B2O6 is present in a target can maintain a fine structure, and enables the provision of a sintered body for magnetic recording film formation use which comprises a sintered body that is stable in water.

Description

Sintered body, sputtering target for forming a magnetic recording film composed of the sintered body

The present invention relates to a sintered body, and relates to a sintered body which can be used for forming a magnetic recording film, and a sputtering target composed of the sintered body, the magnetic recording film being attached to a magnetic film of a magnetic recording medium (especially using a vertical The user of the magnetic recording layer of the magnetic recording type hard disk is formed by film formation.

In the case where sputtering is performed using a target obtained by a sintering system containing boron oxide, since boron oxide particles become coarse at the time of sintering or after sintering, there is a problem that generation of particles frequently occurs during sputtering.

The invention of the present invention relates to a sintered body which can solve such a problem and a sputtering target composed of the sintered body.

In the field of magnetic recording represented by a hard disk drive, as a magnetic thin film material for recording, a material based on a ferromagnetic metal Co, Fe or Ni has been used. For example, in a recording layer of a hard disk using an in-plane magnetic recording method, a Co-Cr-based or Co-Cr-Pt-based ferromagnetic alloy containing Co as a main component has been used.

In addition, a composite material composed of a Co-Cr-Pt-based ferromagnetic alloy containing Co as a main component and a non-magnetic inorganic material is often used for a recording layer of a hard disk using a perpendicular magnetic recording method which has been put into practical use in recent years.

Moreover, in terms of high productivity, the magnetic recording medium such as a hard disk is magnetic thin. Many of the films are produced by sputtering a strong magnetic material sputtering target containing the above materials as a component. Further, in such a sputtering target for a magnetic recording film, boron oxide is added in order to magnetically separate the alloy phase.

For the production method of a strong magnetic material sputtering target, a melting method or a powder metallurgy method is conceivable. The method to be used for fabrication depends on the required characteristics, so it cannot be generalized. However, the sputtering target composed of ferromagnetic alloy and non-magnetic inorganic particles used in the recording layer of the hard magnetic recording type hard disk is generally used. It is produced by powder metallurgy. This is because it is necessary to uniformly disperse inorganic particles such as boron oxide in the alloy base material, and thus it is difficult to produce by the melting method.

On the other hand, when searching for a known document in which boron oxide is added to a magnetic recording medium, the following patent documents are mentioned.

Patent Document 1 discloses a magnetic recording medium having a magnetic data recording layer containing: a first alloy having at least 0.5 × 10 ⁷ erg/cm ³ (0.5/Jcm ³ ) a magnetic anisotropy constant; and an oxide compound composed of one or more elements having oxygen and at least one element having a negative reduction potential" (Request 1).

The magnetic recording medium of claim 1, wherein at least one of the one or more elements of the oxidized compound is selected from the group consisting of lithium (Li), bismuth (Be). ), boron (B), sodium (Na), magnesium (Mg), aluminum (Al), strontium (Si), potassium (K), calcium (Ca), strontium (Sc), titanium (Ti), vanadium (V) ), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), gallium (Ga), antimony (Rb), antimony (Sr), antimony (Y) ), zirconium (Zr), niobium (Nb), cadmium (Cd), indium (In), antimony (Cs), barium (Ba), lanthanum (La), cerium (Ce), cerium (Pr), cerium (Nd) ), 钐 (Sm), 铕 (Eu), 鋱 (Tb), 釓 (Gd), 鈥 (Ho), 铒 (Er), 銩 (Tm), 镱 (Yb), 镏 (Lu), 铪 (Hf ), tantalum (Ta), tungsten (W), lead (Pb), tantalum (Th), and uranium (U), and their materials are sputtering targets.

Although a large amount of oxides described above are also described as boron oxide, the problem of the presence of boron oxide in the target and the solution to this problem are not described at all.

The claim 1 of the following Patent Document 2 describes "a target for a user who forms a Co-based magnetic layer of a magnetic recording medium by a sputtering method, and the target contains 5 mol% or more of Cr. Or a Cr alloy containing 5 mol% or more of CoO, and an oxide having a melting point of 800 ° C or less in a total range of 3 mol % to 20 mol %, and a porosity of 7% or less", the same as the cited claim The target of any one of claims 1 to 3, wherein the oxide having a melting point of 800 ° C or less is selected from the group consisting of boron oxide, vanadium oxide, cerium oxide, molybdenum oxide, and low melting point glass. At least one kind."

In this case as well as the above-mentioned Patent Document 1, the problem of the presence of boron oxide in the sintered body or the target made of the sintered body and the solution to this problem are not described at all.

Patent Document 3 discloses "a sputtering target which is a sintered sputtering target in which a Cr is contained in an amount of 20 mol% or less and a Co magnetic alloy and a non-metallic inorganic material remain as a non-metallic inorganic material. The metal inorganic material occupies a volume fraction of 40 vol% or less, and the non-metal inorganic material contains at least cobalt oxide and boro oxide. A method for producing a sintered body for a sputtering target, which is a metal powder and at least cobalt A mixed powder obtained by pulverizing and mixing a non-metallic inorganic material powder of an oxide and a boron oxide is molded and sintered by a pressure sintering device at a temperature of 800 ° C or lower (Abstract).

In this case, similarly to the above-mentioned Patent Documents 1 and 2, although it is described that "boron oxide" is contained, the problem of the presence of boron oxide in the target and the solution to this problem are not described at all.

In the following Patent Document 4, "a sputtering target for a magnetic recording film containing SiO ₂ and containing B (boron) in an amount of 10 to 1000 wtppm" is described. In this case, boron oxide is contained. However, similarly to the above-mentioned Patent Documents 1, 2, and 3, the problem of the presence of boron oxide in the sintered body or the target made of the sintered body is not described at all, and a solution to this problem is provided.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-59733

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2012-33247

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2012-117147

[Patent Document 4] Japanese Patent No. 5009448

For the sputtering target for a magnetic recording film, a composite material composed of a ferromagnetic alloy and a non-magnetic material is often used, and boron oxide is added as a non-magnetic material. However, since the target of boron oxide is added, since the boron oxide particles become large after sintering, if the sintering temperature for suppressing the growth of the particles is lowered, the density cannot be increased, and a large amount of particles are generated.

If you ask this question, you can see that the reasons are roughly divided into two types. First: Since the boron oxide raw material has high hygroscopicity and is easily solidified, it is difficult to obtain fine boron oxide. Second: Since boron oxide has a low melting point, it is easily liquefied during sintering and grows into large particles during sintering.

Further, as another problem, when the sintered body in which boron oxide remains is wet-processed by machining or the like, or when stored in a place having high humidity, it reacts with moisture to form boric acid, which is formed in a sintered body (target). The surface or the like precipitates to cause stains or contamination, which is also a cause of particles generated during sputtering, and causes moisture to enter the film and causes defects.

In order to ensure good quality of a sintered body (particularly a sputtering target) for forming a magnetic recording film to which boron oxide is added, such a problem must be solved.

Based on this knowledge insight, the present invention provides

1) A sintered body composed of a metal or an alloy containing at least one of boron and/or a platinum group element and an oxide, and characterized in that a phase composed of the oxide exists At least one of Cr(BO ₃ ), Co ₂ B ₂ O ₅ and Co ₃ B ₂ O ₆ .

Also, the present invention provides

2) A sintered body comprising a metal or an alloy and an oxide containing at least one of chromium and a boron and/or a platinum group element, and characterized in that it is composed of the oxide. At least one of Cr(BO ₃ ), Co ₂ B ₂ O ₅ , and Co ₃ B ₂ O _{6 is present} in the phase.

Also, the present invention provides

3) The sintered body according to the above 1) or 2), wherein the surface of the sintered body does not discolor when the sintered body is in contact with water or immersed in water.

Also, the present invention provides

4) The sintered body according to 2) or 3) above, wherein the atomic ratio of chromium to boron is Cr/B≧1.

Also, the present invention provides

The sintered body according to any one of the above 1 to 4, wherein the atomic ratio of boron to oxygen is B/O ≦ 0.5.

Also, the present invention provides

The sintered body according to any one of the above 1 to 5, wherein, in the ratio of the metal component, the chromium content is 0 to 50 mol%, and the boron and/or platinum group element content is 0 (only, excluding 0) ~ 40mol%, the remainder is cobalt.

Also, the present invention provides

The sintered body according to any one of the above 1 to 6, wherein the content of boron oxide is 0.5 to 10 mol% in terms of B ₂ O ₃ .

Also, the present invention provides

The sintered body according to any one of the above 1 to 7, wherein the total content of the chromium oxide is 0.5 to 10 mol% in terms of Cr ₂ O ₃ .

Also, the present invention provides

The sintered body according to any one of the above 1 to 8, further comprising a member selected from the group consisting of Al, Co, Cu, Fe, Ga, Ge, Hf, Li, Mg, Mn, Mo, Nb, Ni, Sb An oxide of one or more of Si, Sn, Ta, Te, Ti, V, W, Y, Zn or Zr as a constituent component, and the total amount of oxide is 2 to 8 wt% in terms of oxygen.

Also, the present invention provides

The sintered body according to any one of the above 1 to 9, wherein the oxide in the sintered body has an average area per particle of 2 μm ² or less.

Also, the present invention provides

The sintered body according to any one of the above 1 to 10, further comprising 0.5 mol% or more and 10 mol% or less of one element selected from the group consisting of Ti, V, Mn, Zr, Nb, Mo, Ta, and W the above.

Also, the present invention provides

The sintered body according to any one of the above 1 to 11, further comprising one or more selected from the group consisting of carbon, nitride, and carbide.

Also, the present invention provides

13) The sintered body according to any one of the above 1) to 12), which has a relative density of 95% or more.

Also, the present invention provides

14) A sputtering target for forming a magnetic recording film, comprising the sintered body according to any one of the above 1) to 13).

Also, the present invention provides

15) A method for producing a sintered body comprising at least one or more metals or alloys selected from the group consisting of boron and/or a platinum group element, and Cr(BO ₃ ), Co ₂ B ₂ O ₅ , Co At least one or more of the ₃ B ₂ O ₆ oxides are mixed and sintered.

Also, the present invention provides

16) A method for producing a sintered body, which comprises at least one metal or alloy selected from the group consisting of chromium and boron and/or a platinum group element, and Cr(BO ₃ ), Co ₂ B ₂ O ₅ At least one or more of the oxides of Co ₃ B ₂ O ₆ are mixed and sintered.

Also, the present invention provides

(17) The method for producing a sintered body according to the above 15) or 16), which comprises preparing boron oxide, chromium oxide and/or cobalt oxide, and firing the same in the atmosphere to produce Cr(BO ₃ ), Co ₂ B ₂ At least one or more oxides of O ₅ and Co ₃ B ₂ O ₆ .

Also, the present invention provides

(18) A sintered body of any one of the above items 1) to 13), wherein the sintered body of any one of the above items 1) to 13) is produced by the method for producing a sintered body according to any one of the above items 15) to 17).

As described above, the sintered body to which boron oxide is added has a large amount of boron oxide particles after sintering, and when a sputtering target for forming a magnetic recording film is used, there is a problem that a large amount of particles are generated. The reason for this is that since the boron oxide raw material has high hygroscopicity and is easily solidified, it is difficult to obtain fine boron oxide, and boron oxide has a low melting point, so that it is easily liquidified during sintering and grows large during sintering. particle.

In view of the above, in the sintered body of the present invention (particularly, a sputtering target for a magnetic recording film), Cr(BO ₃ ), Co ₂ B ₂ O ₅ , and Co ₃ B ₂ O ₆ are present in a phase composed of an oxide. At least one of the above.

These compounds of Cr(BO ₃ ), Co ₂ B ₂ O ₅ , and Co ₃ B ₂ O ₆ have the following characteristics: they can maintain a fine structure and increase the melting point of boron oxide, thereby suppressing reaction with water. Thereby, the above problems caused by boron oxide in the sintered body can be solved.

In other words, it is possible to ensure good quality of a sintered body to which boron oxide is added (especially, a sputtering target for a magnetic recording film), and it is possible to suppress generation of particles during sputtering. In addition, when the sintered body in which boron oxide remains is subjected to wet processing by machining or the like, or when stored in a place having high humidity, it reacts with moisture to form boric acid, which is deposited on the surface of the sintered body (target). It becomes the cause of stains or pollution, but the same can be solved.

Since the generation of particles can be suppressed as such, the magnetic recording film has a significant effect of reducing the defective rate and reducing the cost, and contributes greatly to the improvement of the quality and production efficiency of the magnetic film.

The sintered body of the present invention (particularly, a sputtering target for a magnetic recording film) is composed of a metal or an alloy containing at least one or more selected from the group consisting of chromium and a platinum group, and an oxide containing boron oxide and chromium oxide. A sintered body (particularly a sputtering target for a magnetic recording film). In addition to the above (other than the above-described component composition), other metal materials or inorganic materials to be described later may be further added.

In addition, the above-mentioned "metal or alloy selected from one or more of chromium and platinum group elements" means that it may be a simple metal of chromium metal, or may be one or two or more metals selected from the group consisting of platinum group elements, or may be It is an alloy for it.

Further, the sintered body of the present invention is mainly used as a sputtering target. In view of the above, the sputtering target which is mainly used will be mainly described below, but the sintered body is not limited to use in other coating methods. For example, it can also be used for physical or chemical vapor deposition methods such as ion beam evaporation. The sintered body of the invention of the present invention contains the same.

The invention of the present invention is characterized in that at least one of Cr(BO ₃ ), Co ₂ B ₂ O ₅ and Co ₃ B ₂ O ₆ is present in the phase composed of the above oxide, which is one of the important technical features of the invention of the present invention. . By the presence of boron oxide in the form of the above-mentioned compound, it is possible to maintain a fine structure and increase the melting point of boron oxide, and it is possible to have characteristics and effects of suppressing reaction with water.

The compound can be stabilized in the sintered body by using a raw material which is formed in the form of the above-mentioned compound beforehand, and the compound remains. However, the same effect can be obtained if the above compound can be produced by reaction sintering or the like. The above compounds may be present as long as they can be subjected to XRD measurement of the sample collected from the sintered body and define the peak of the compound phase.

In the sintered body of the present invention, it is preferred that the atomic ratio of chromium to boron is Cr/B≧1. This was confirmed by experiments because it became easy to react with water if it fell outside the range. Although the range outside this range can also be used, this atomic ratio is a better range.

Further, in the sintered body of the present invention, it is preferred that the atomic ratio of boron to oxygen is B/O≦ 0.5. This was confirmed by experiments because it became easy to react with water if it fell outside the range. Although the range outside this range can also be used, this atomic ratio is a better range.

The sintered body of the present invention (particularly, a sputtering target for a magnetic recording film) can be applied to a general magnetic target, but a representative and preferable magnetic material has a chromium content of 0 to 50 mol%, boron and/or a platinum group. The content of the element is 0 (only, excluding 0) ~ 40 mol%, and the remainder is cobalt. In this case, it is the same as the above, and means that it may be a simple substance of chrome metal, or a metal selected from one or more of boron and/or a platinum group element, or an alloy thereof.

The present invention has a focus on the present invention in that it contains boron oxide in the above-described form. Therefore, it is not necessary to be limited to the above composition range. However, the basic composition of the preferred magnetic material is as described above.

In the sintered body of the present invention (particularly, a sputtering target for a magnetic recording film), the content of boron oxide (which may also be referred to as an addition amount) is 0.5 to 10 mol% in terms of B ₂ O ₃ . The boron contained as a component is preferably present in a form of any one of Cr(BO ₃ ), Co ₂ B ₂ O ₅ , and Co ₃ B ₂ O ₆ .

The total content of chromium oxide is preferably 0.5 to 10 mol% in terms of Cr ₂ O ₃ . This is also a preferred range of performance as a sputtering target for magnetic recording films.

In addition to the oxides described above, it is selected from the group consisting of Al, Co, Cu, Fe, Ga, Ge, Hf, Li, Mg, Mn, Mo, Nb, Ni, Sb, Si, Sn, Ta, Te, Ti, One or more elements of V, W, Y, Zn or Zr are oxides as constituent components, and the total amount of oxide is 2 to 8 wt% in terms of oxygen. This is also a preferred range of performance as a sintered body (particularly, a sputtering target for a magnetic recording film).

The addition of these oxides is not particularly shown in the examples, but a preferred material generally added to the magnetic recording film can be similarly applied in the present invention.

In the sintered body of the present invention (particularly, a sputtering target for a magnetic recording film), the average area of each of the oxide phases is preferably 2 μm ² or less. In general, the oxide phase can be observed by grinding (as needed with the grinding) of the target surface, preferably with fine dispersion of the oxide phase.

The reason for this is that if a coarsened oxide phase is present, it becomes easy to cause an arc or a particle at the time of sputtering. Further, the above-mentioned area indicates a preferable range as a sputtering target for a magnetic recording film, and depending on the purpose of use or the association with other materials, the range beyond which it is used is not hindered.

The sintered body of the present invention (particularly, a sputtering target for a magnetic recording film) described above is further contained in an amount of 0.5 mol% or more and 10 mol% or less selected from the group consisting of Ti, V, Mn, Zr, Nb, Mo, and Ta. One element of W or more is added as a simple element. These additional elements are added as needed in order to improve the characteristics of the magnetic recording medium.

Although the additive elements are not particularly shown in the examples, they are preferred materials which are generally added to the magnetic recording film, and can be similarly applied in the present invention.

Similarly, an inorganic material selected from the group consisting of carbon, nitride, and carbide may be contained as an additive material. These are also elements which are added as needed in order to improve the characteristics of the magnetic recording medium.

With respect to the sintered body of the present invention (particularly, a sputtering target for a magnetic recording film) having the above composition, the relative density can be 95% or more, further 98% or more, or even 99% or more. Although the density of the sintered body can be adjusted by the sintering temperature and the pressure of hot pressing or HIP, if the temperature is too high, the oxide phase particles grow and coarsen. Therefore, it is preferable to lower the sintering temperature and increase the pressure as much as possible. Preferably, the sintering temperature is 1100 ° C or lower and the pressure is 250 kgf / cm ² or more. The molding/sintering is not limited to hot pressing, and a plasma discharge sintering method or a hot hydrostatic sintering method may also be used.

Furthermore, relative density refers to the value obtained by dividing the measured density of the target by the calculated density (also known as the theoretical density). The calculated density is calculated by the following formula assuming that the constituent components of the target do not diffuse or react under the mixing.

Formula: Calculated density = sigma Σ (molecular weight of constituent components × molar ratio of constituent components) / Σ (molecular weight of constituent components × molar ratio of constituent elements / literature value density of constituent components) Here, Σ means the target All constituents are summed.

In the following, a part of the composition range of the invention of the present invention is exemplified by the examples (representative examples), but the sintered body (especially the sputtering target for magnetic recording film) having the composition range specified in the invention of the present invention has the following implementation The same effect.

[Examples]

Hereinafter, it demonstrates based on an Example and a comparative example. In addition, this embodiment is only an example and is not limited by this illustration. That is, the present invention is limited only by the scope of the patent application, and includes various modifications other than the embodiments included in the invention.

(Example 1)

Prepare boron oxide and chromium oxide or cobalt oxide, and weigh them into B ₂ O ₃ :Cr ₂ O ₃ =1:1, B ₂ O ₃ :CoO=1:2, B ₂ O ₃ :CoO=1:3, After mixing in a ball mill, it is fired in the air at a temperature of 700 to 1200 ° C for more than five hours, thereby producing a material selected from the group consisting of Cr(BO ₃ ), Co ₂ B ₂ O ₅ , and Co ₃ B ₂ O ₆ . One or two or more compounds. Further, it is also possible to change the blending ratio and adjust the compound to a plurality of compounds and a simple oxide.

Further, these are pulverized to form a sintered raw material (oxide). Further, it is also possible to change the blending ratio and adjust the compound to a plurality of compounds and a simple oxide. A ball mill is used for pulverization.

Next, the sintered raw material and the raw material powder containing at least one of chromium and a metal selected from the group consisting of chromium and a platinum group element, and a raw material powder of an optional oxide are adjusted to the ratio shown in Table 1, using a ball mill. After mixing for more than 20 hours, fill in a diameter of 50 The graphite mold is hot pressed and sintered at a sintering temperature of 900 to 1100 ° C in a vacuum.

Then, the disk shape was formed by mechanical processing, and then immersed in pure water at room temperature for 1 hour, and then dried to observe the surface. In addition, the manufacturing method and test method of the following examples and comparative examples are also the same conditions as this embodiment.

The composition of each component of the magnetic material formed as a matrix in Example 1 was set to Co: 69 mol%, Cr: 5 mol%, and Pt: 20 mol%. On the other hand, the oxide is made of Cr(BO ₃ ): 2 mol%, Cr ₂ O ₃ : 2 mol%, and SiO ₂ : 2 mol%. The Cr/B ratio was 5.5. Also, the B/O ratio is 0.1. They satisfy the conditions of the invention of the present invention.

The results are shown in Table 1. The average area of each particle of the oxide phase in the target was 1.5 μm ² . Further, the average area of each particle of the oxide phase was determined as follows. First, the surface of the sample arbitrarily collected from the target was ground to a mirror surface, and a laser microscope image was photographed at a field of 25 × 18 μm. Since the oxide phase and the metal phase are greatly different in reflectance, discrimination is made by the difference in brightness between the images.

From this, the total area and number of oxide phases were determined, and the average area of each particle (the total area of the oxide phase) was calculated. The following examples and comparative examples were also calculated in the same manner. In the above calculation, the software (shape analysis application VK-H1A1 manufactured by KEYENCE Corporation) was used to obtain the laser microscope image.

The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 96.5%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to produce a target and sputtering was performed. As a result, the number of particles generated in a constant state was two, and as described above, a high-density target was obtained, and the number of particles generated was small.

(Example 2)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be a matrix of Example 2 was set to Co: 60 mol%, Cr: 5 mol%, Pt: 20 mol%, and Ru: 5 mol%.

On the other hand, the oxide was set to Cr (BO ₃ ): 10 mol%. The Cr/B ratio was 1.5. Also, the B/O ratio is 0.3. They satisfy the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.9 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 95.8%.

(Example 3)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be the matrix of Example 3 was set to Co: 77.8 mol%, Cr: 5.3 mol%, and Pt: 10.5 mol%.

On the other hand, the oxide was made of Cr(BO ₃ ): 4.2 mol%, Co ₂ B ₂ O ₅ : 1.1, and Co ₃ B ₂ O ₆ : 1.1. The Cr/B ratio was 1.7. Also, the B/O ratio is 0.3. They satisfy the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.1 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 96.1%.

(Example 4)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material of the substrate of Example 4 was set to Co: 75.2 mol%, and Pt: 21.5 mol%.

On the other hand, the oxide was set to Co ₂ B ₂ O ₅ : 2.2 and Co ₃ B ₂ O ₆ : 1.1. The Cr/B ratio is 0.0. Also, the B/O ratio is 0.4. They satisfy the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 2.0 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 97.1%.

(Example 5)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be the matrix of Example 5 was set to Co: 71.4 mol%, and Pt: 20.4 mol%.

On the other hand, the oxide was Cr (BO ₃ ): 4.1 mol%, Co ₂ B ₂ O ₅ : 1, and TiO ₂ : 3.1 mol%. The Cr/B ratio was 0.7. Also, the B/O ratio is 0.3. In addition to the Cr/B ratio, the conditions of the invention of the present invention are satisfied.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.2 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 97.5%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to produce a target and sputtering was performed. As a result, the number of particles generated in a constant state was three, and as described above, a high-density target was obtained, and the number of particles generated was small.

(Example 6)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be a matrix of Example 6 was set to Co: 55 mol%, Cr: 30 mol%, and Ru: 5 mol%.

On the other hand, the oxide was made of Cr(BO ₃ ): 2 mol%, and TiO ₂ : 8 mol%. The Cr/B ratio is 16. Also, the B/O ratio is 0.09. Either of them satisfies the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.9 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 99.5%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to form a target and sputtering was performed. As a result, the number of particles generated in a constant state was nine, and as described above, a high-density target was obtained, and the number of particles generated was small.

(Example 7)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be the matrix of Example 7 was set to Co: 55 mol%, Cr: 30 mol%, and B: 5 mol%.

On the other hand, the oxide was set to CoO: 6 mol%, and TiO ₂ : 4 mol%. The Cr/B ratio is 6. Also, the B/O ratio was 0.36. Either of them satisfies the conditions of the invention of the present invention.

After the sintering, it was confirmed by XRD measurement of the sample that a part of Cr (BO ₃ ) was formed. XRD measurement conditions were: Ultima IV manufactured by Rigaku Corporation, CuK α ray, tube voltage: 40 kV, tube current: 30 mA, scanning speed: 1°/min, step width: 0.01°, scanning angle range (2 θ): 24°~35°. It can be confirmed by a peak which does not overlap with the peak of the other product among the first peak of Cr(BO ₃ ) expressed in the vicinity of 33.79° or the second peak of Cr(BO ₃ ) which is expressed near 25.68°.

In this embodiment, the intensity of the first peak is 120 cps, and the intensity of the second peak is 70 cps (background intensity is about 50 cps). In addition, since the intensity value of these changes by the measurement conditions and the sample adjustment, the above numerical value is only an example, and is not limited by the numerical value.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.9 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 99%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to produce a target and sputtering was performed. As a result, the number of particles generated in a constant state was 10, and as described above, a high-density target was obtained, and the number of particles generated was small.

(Example 8)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be the matrix of Example 8 was set to Co: 60 mol%, Cr: 5 mol%, and Pt: 24 mol%.

On the other hand, the oxide was made of Cr(BO ₃ ): 4 mol%, SiO ₂ : 4 mol%, and CoO: 3 mol%. The Cr/B ratio was 2.25. Also, the B/O ratio was 0.17. Either of them satisfies the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.1 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 99.2%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to produce a target and sputtering was performed. As a result, the number of particles generated in a constant state was four, and as described above, a high-density target was obtained, and the number of particles generated was small.

(Example 9)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material of the substrate of Example 9 was set to Co: 73 mol%, Cr: 2 mol%, and Pt: 17 mol%.

On the other hand, the oxide is made of Cr(BO ₃ ): 2 mol%, Ta ₂ O ₅ : 2 mol%, and WO ₃ : 4 mol%. The Cr/B ratio is 2. Also, the B/O ratio was 0.07. Either of them satisfies the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.5 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 98%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to produce a target and sputtering was performed. As a result, the number of particles generated in a constant state was five, and as described above, a high-density target was obtained, and the number of particles generated was small.

(Embodiment 10)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be the matrix of Example 10 was set to Co: 65 mol%, Cr: 4 mol%, and Pt: 25 mol%.

On the other hand, the oxide is Cr (BO ₃ ): 2 mol%, B ₂ O ₃ : 2 mol%, and Nb ₂ O ₅ : 2 mol%. The Cr/B ratio is 1. Also, the B/O ratio was 0.27. Either of them satisfies the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.6 μm ² . The surface of the sintered body immersed in water showed no discoloration at all. Further, the sintered body had a relative density of 98.8%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to form a target and sputtering was performed. As a result, the number of particles generated in a constant state was six, and as described above, a high-density target was obtained, and the number of particles generated was small.

(Comparative Example 1)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be a matrix of Comparative Example 1 was set to Co: 63 mol%, Cr: 5 mol%, Pt: 20 mol%, and Ru: 5 mol%.

On the other hand, the oxide is B ₂ O ₃ : 5 mol%, and SiO ₂ : 2 mol%. The Cr/B ratio is 0.5. Further, the B/O ratio was 0.5, and no compound of Cr(BO ₃ ), Co ₂ B ₂ O ₅ or Co ₃ B ₂ O _{6 was} observed in the sintered body. They did not satisfy the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 4.3 μm ² . The surface of the sintered body immersed in water is discolored in appearance. Further, the sintered body had a relative density of 96%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to produce a target and sputtering was performed. As a result, the number of particles generated in a constant state was 20, and the number of particles generated was large.

(Comparative Example 2)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1. However, the compound powder of Cr(BO ₃ ), Co ₂ B ₂ O ₅ , and Co ₃ B ₂ O _{6 was} not produced beforehand.

The composition of each component of the magnetic material to be the matrix of Comparative Example 2 was set to Co: 68 mol%, Cr: 5 mol%, and Pt: 20 mol%. On the other hand, the oxide is B ₂ O ₃ : 5 mol%, and Cr ₂ O ₃ : 2 mol%. The Cr/B ratio was 0.9. Also, the B/O ratio is 0.5. The Cr/B ratio did not satisfy the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 1.8 μm ² . The surface of the sintered body immersed in water is discolored in appearance. Further, the sintered body had a relative density of 93%. Dimensions 180 made from the same raw materials and manufacturing conditions The sintered body was used to produce a target and sputtering was performed. As a result, the number of particles generated in a constant state was 34, and as described above, a target having a low density was obtained, and the number of particles generated was large.

(Comparative Example 3)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be a matrix of Comparative Example 3 was set to Co: 73 mol%, and Pt: 20 mol%. On the other hand, the oxide is B ₂ O ₃ : 6 mol%, and Co ₃ B ₂ O ₆ : 1 mol%. The Cr/B ratio is zero. Also, the B/O ratio is 0.6. They did not satisfy the conditions of the invention of the present invention.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 5.1 μm ² . The surface of the sintered body immersed in water is discolored in appearance. Further, the sintered body had a relative density of 96.3%.

(Comparative Example 4)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be a matrix of Comparative Example 4 was set to Co: 66 mol%, Cr: 9 mol%, and B: 10 mol%. On the other hand, the oxide was set to CoO: 7 mol%, and TiO ₂ : 8 mol%. The Cr/B ratio was 0.9. Also, the B/O ratio is 0.43. The conditions of the invention of the present invention were not met. Further, in the XRD measurement of the sample after sintering, it was not confirmed that Cr (BO ₃ ) was formed.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 3.8 μm ² . The surface of the sintered body immersed in water is discolored in appearance. The Cr/B ratio is relatively small, and as a result of the large amount of Cr amount B, it is considered that a large amount of boron oxide is generated and coarsening of the oxide particles occurs. Further, the sintered body had a relative density of 99.0%.

(Comparative Example 5)

A sintered body was produced under the same conditions as in Example 1 except that the composition of each component was adjusted to Table 1.

The composition of each component of the magnetic material to be the matrix of Comparative Example 5 was set to Co: 50 mol%, Cr: 30 mol%, and Ru: 10 mol%. On the other hand, the oxide is B ₂ O ₃ : 7 mol%, and SiO ₂ : 3 mol%. The Cr/B ratio was 2.1. Also, the B/O ratio was 0.52. The conditions of the invention of the present invention were not met. Further, in the XRD measurement of the sample after sintering, it was not confirmed that Cr (BO ₃ ) was formed.

The results are also shown in Table 1. The average area of each particle of the oxide phase in the target was 8.2 μm ² . The surface of the sintered body immersed in water is discolored in appearance. The reason for this is considered to be the coarsening of the oxide particles caused by the presence of boron oxide. Further, the sintered body had a relative density of 99.2%.

[Industrial availability]

In the past, a sintered body to which boron oxide is added as an inorganic material (particularly, a sputtering target for a magnetic recording film) has a problem that the particles of boron oxide are large after sintering, and the density cannot be increased by reducing the sintering temperature in order to suppress particle growth. A large amount of particles are produced.

The reason for this is that since the boron oxide raw material has high hygroscopicity and is easily solidified, it is difficult to obtain fine boron oxide, and boron oxide has a low melting point, so that it is easily liquidified during sintering. The knot will grow into large particles.

In view of the above, the sintered body of the present invention (particularly, a sputtering target for a magnetic recording film) is formed such that Cr (BO ₃ ), Co ₂ B ₂ O ₅ , and Co ₃ B are present in a phase composed of an oxide. At least one of ₂ O ₆ .

These compounds of Cr(BO ₃ ), Co ₂ B ₂ O ₅ , and Co ₃ B ₂ O ₆ have the following characteristics: they can maintain a fine structure and increase the melting point of boron oxide, thereby suppressing reaction with water. Thereby, the above problems caused by boron oxide can be solved. In this way, it is possible to ensure good quality of a sintered body to which boron oxide is added (especially, a sputtering target for a magnetic recording film), and it is possible to suppress generation of particles during sputtering.

In addition, when the sintered body in which boron oxide remains is subjected to wet processing by mechanical processing or the like, or when stored in a place having high humidity, boric acid is generated by reaction with water, and precipitates on the target surface or the like to cause stains or contamination. The reason, but the same can be solved.

Since it can suppress the generation of particles, it has a significant effect of reducing the defect rate of the magnetic recording film and reducing the cost, and greatly contributes to improving the quality and production efficiency of the magnetic film, and is suitable for a magnetic film (especially hard) as a magnetic recording medium. A strong magnetic material sputtering target used for film formation of a disk drive recording layer).

Claims (18)

A sintered body comprising at least one metal or alloy selected from the group consisting of boron and/or a platinum group element and an oxide, and characterized in that Cr is present in a phase composed of the oxide ( At least one of BO ₃ ), Co ₂ B ₂ O ₅ and Co ₃ B ₂ O ₆ . A sintered body composed of a metal or an alloy and an oxide containing at least one of chromium and a boron and/or a platinum group element, and characterized in that a phase composed of the oxide exists At least one of Cr(BO ₃ ), Co ₂ B ₂ O ₅ and Co ₃ B ₂ O ₆ . A sintered body according to claim 1 or 2, wherein the surface of the sintered body does not discolor when the sintered body is in contact with water or immersed in water. The sintered body of claim 2, wherein the atomic ratio of chromium to boron is Cr/B≧1. The sintered body according to any one of claims 1 to 4, wherein the atomic ratio of boron to oxygen is B/O ≦ 0.5. The sintered body according to any one of claims 1 to 5, wherein, in the ratio of the metal component, the chromium content is 0 to 50 mol%, and the boron and/or platinum group element content is 0 (only, excluding 0) ~ 40mol%, the remainder is cobalt. The sintered body according to any one of claims 1 to 6, wherein the content of boron oxide is 0.5 to 10 mol% in terms of B ₂ O ₃ . The sintered body according to any one of claims 1 to 7, wherein the total content of chromium oxide is 0.5 to 10 mol% in terms of Cr ₂ O ₃ . The sintered body according to any one of claims 1 to 8, further comprising a member selected from the group consisting of Al, Co, Cu, Fe, Ga, Ge, Hf, Li, Mg, Mn, Mo, Nb, Ni, Sb An oxide of one or more of Si, Sn, Ta, Te, Ti, V, W, Y, Zn or Zr as a constituent component, and the total amount of oxide is 2 to 8 wt% in terms of oxygen. The sintered body according to any one of claims 1 to 9, wherein an average area of each of the oxides in the sintered body is 2 μm ² or less. The sintered body according to any one of claims 1 to 10, further comprising 0.5 mol% or more and 10 mol% or less of one element selected from the group consisting of Ti, V, Mn, Zr, Nb, Mo, Ta, and W the above. The sintered body according to any one of claims 1 to 11, further comprising one or more selected from the group consisting of carbon, nitride, and carbide. The sintered body according to any one of claims 1 to 12, which has a relative density of 95% or more. A sputtering target for forming a magnetic recording film, which is composed of the sintered body of any one of the above claims. A method for producing a sintered body, which comprises at least one metal or alloy selected from the group consisting of boron and/or a platinum group element, and Cr(BO ₃ ), Co ₂ B ₂ O ₅ , Co ₃ B At least one or more of the oxides of ₂ O ₆ are mixed and sintered. A method for producing a sintered body, which comprises at least one metal or alloy selected from the group consisting of chromium and boron and/or a platinum group element, and Cr(BO ₃ ), Co ₂ B ₂ O ₅ , Co At least one or more of the ₃ B ₂ O ₆ oxides are mixed and sintered. The method for producing a sintered body according to claim 15 or 16, wherein the boron oxide, the chromium oxide and/or the cobalt oxide are prepared and fired in the atmosphere to produce Cr(BO ₃ ), Co ₂ B _{2 .} At least one or more oxides of O ₅ and Co ₃ B ₂ O ₆ . A method of producing a sintered body, which is produced by the method of producing a sintered body according to any one of claims 15 to 17, wherein the sintered body according to any one of claims 1 to 13 is produced.